Tube-expanding tool



TUBE EXPANDNG rIYOOL' Filed Jan. l1 1922 mh@ Wip lIt() Patented Nov. 25, i924.

uNrrEn srriis CARL 1F. BRAUN, OF SAN FRANCISCO; CALIFORNIA.

TUBE-EXPANDING TOOL.

Application led January 11, 1922.

To all whom t may concern.'

Be it known that I, CARL F. BRAUN, a citizen of the United States, residing at the city and county of San Francisco, and State of California, have invented new and useful Improvements in Tube-Expanding Tools, of which the following is a specifica-- tion.

This invention relates to a machine tool, and particularly pertains tota tube expanding tool. y

It is common practice to passl tubes through sheets and to thereafter expand the tubes into the openings through which they pass, whereby Ya tight joint will be eected 4between the tube sheet and the tube.

In carrying out this operation it often happens that the tubes are ruptured and in some cases objectionably distended at points along their length. Certain types oi expanding tools also turn the ends et the tube over .the -outer face 0'1"' the tube sheet. In either event, an objectionable structure is formed, 'as the tubes readily rupture, and when removed require that the tube be destroyed, and in some instances that the tube nest be dismantled. Certain types of expanding tools also act to exert inward pressure on the tubes, thus causing them to buckle between the plates.

With these objections in mind, it is the principal object of the present invention to provide a tube expanding tool which will. quickly expand the tube within the opening through which it passes, at the same time insuring that the tube will n-ot be buckledwill not be objectionably distended at points along itslength, and that it will draw the metal of the tube ina manner to prevent crystallization or rupture ot the Wall;

The present invention contemplates `the use of a rotary body member adapted to be inserted into the open end ot a tube, said member carrying outwardly movable rollers which act to spin the metal of the tube wall and tend to draw the surplus metal outwardly, said rollers and body member being driven and operated by a centrallv disposed tapered mandrel. l.

The invention is illustrated by way of example in the accompanying drawing, in which:

Fig. 1 is a view in elevation showing the complete tool.

Serial No. 528,479.

Fig. 2 is a View in transverse section through the tool as seen on the line. 2--2 ot Fig. l..

Fig. 3 is a view in section and elevation showing the relative initial positions of the parts of the tool.

Fig. 4 is a view similar to Fig. 3 showing the expanding action of the rollers.

Referring more particularly to the drawing, 10 indicates a body member of the expanding tool. This member is formed with a sleeve 11 enlarged at one end to provide a head 12. The sleeve substantially agrees in outer diameter with the inside diameter of a tube 13 which is to be expanded. The enlarged head 12 is larger in diameter than the outside diameter of the tube, thus permit-ting an annular recess 14 to be formed around the end ot the head abutting against al tube sheet 15. The width of this recess is sufficient to accommodate surplus metal of the tube wall in a manner which will be hereinafter described.

Longitudinally extending slots 16 are formed through the sleeve 11. These slots are disposed at a slight inclination to the longitudinal center of the body member 10 and receive expanding rollers 17. As shown in Fig. 2 of the drawing, three expanding rollers are provided. These rollers seat within the slots 16, and due to the fact that the opposite side walls of the slots are arcuate as indicated at 18 the rollers will remain within the slots, although they may have considerable lateral play. The rollers are truste-conical in shape, having a slight taper. The bases of the rollers are disposed `near the end of the sleeve portion 11, while the reduced ends ot the rollers extend into continuations of the slots 16, which are .formed through the head 12. A removable `collar 19 is secured against the outer end face of the head by screws 20. This collar prevents longitudinal displacement of the rollers and holds them within the slots. In order to obtain the best results the length ot the rollers extending along the sleeve beyond the shoulder face of the head 12 agrees in dimension with the thickness of the tube sheet 15. This will cause the outer end of the rollers to terminate near the line of the inner face of the tube sheets. In any event it is not desirable to extend the ends of the rollers beyond the inner face of the tube sheet, for then the expanding action of the rollers wouldprobably distend the unsupported wall of the tube near the sheet.

Expanding action is broughtI aboiit by a tapered mandrel 2l, the taper o'l' which inandrel is substantially twice that of the roller taper, thiis insuring that the outer faces ot the rollers will lie parallel with the central axis of the mandrel when the mandrel is forced into the central opening o'l' the body member 10 and into engagement with the various rollers.

In operation oi: the present invention the assembled tool is inserted int-o the open mouth of a tube, it beingunderstood that the tube has previouslyv been positioned through its tube sheet. It is desirable that the end ot the tube shall lie `Hush with the oriter i'ace o'l the tube sheet, as will be hereinater understood. The tapered mandrel may then be inserted into the opening 22 through the body and brought into a wedging position against the rollers 17. At this time it is to be understood that the shoulder face ot' the tool body is resting against the outer face of the tube sheet, as shown in Fig. 3. Suitable means may be provided to rotatethe mandrel in a clockwise direction. For convenience this means may be a portable electric or air motor fitted with a chuck to grip the cylindrical end a3 o't' the mandrel. As the mandrel rotates in a clockwise direction, it will frictionally engage the rollers 17 and will have a tendency to cause the tool body to rotate' in unison therewith, at the saine time the friction of the mandrel on the rollers causing them to roll in a counter direction to that ot the mandrel and the tool body.

Attention is again directed to the fact that the rollers 17 are disposed at anglesto the longitudinal axis oi the tool and it is to be further noted that the smaller' ends of the rollers will be in advance when the tool rotates in a clockwise direction. The counter-clockwise rotation of the rollers at this aliglewvill tend to work the surplus metal of the tube out Tardly as the tool operates.

`This action will not be appreciable until after the rollers have completely expanded the tube into the tube sheet opening. Then the rollers will tend to spin the metal wall of the tribe and lap t-he surplus metal toward the oriter end of the tube as shown in Fig. fl. This surplus metal will extend into the recess 14: of the head l?. and in the event that continued pressure is delivered to the mandrel while rotating it may be possible to la-p sutlicient metal out to crimp the end of the tribe against the tube sheet. This operation is, however, not necessary inthe present instance, as the expanding rollers will insure that a tight joint will be made between the tribes and their sheets, without danger of rupturing the tube walls or lotherwise weakening them. In performing the expanding operation it is only necessary to spin the tool for a few turns in order to siiiiiciently expand the tribe. The workman slightly withdraws the tool at intervals during operation, and when he notices the end of the tribe projecting' from the outer face of the tribe sheet he is thus advised that the joint is sutliciently tight, and that his additional pressure is acting to force the metal longitudinally of the tube as well as expand the tube. The action of the tool also tends to draw the tribes lengthwise, thris straightening them between the tribe sheets and placing' them under a desirable tension.

lt will thus be seen that the device here disclosed provides a simple and el'lectivemeans for rapidly expanding tubes into their sheets in a manner to insure against rupture or breaking of the tribes, and to permit the individual tubes to be readily withdrawn from their sheets.

While I have shown the preferred form or' my invention, as now known to me, it will be understood that various changes might be made in the combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the invention, as claimed;

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A tribe expanding tool comprising means for acting to simultaneously expand the wall of a tribe into an openingin a tribe sheet and draw the metalv of the tribe longitudinally through the opening in the tribe sheet, said means including a member abritting against the face of the tribe sheet and having an annular recess in its abutting Y face concentric with the tribe sheet to receive the drawn out metal at the end of the tribe.

2. A tool for expanding a tube into an opening formed in a tribe sheet, comprising a rotatable member adapted to be inserted into the end of the tribe and having anenlarged head adapted to abut against the outer tace of the tribe sheet, tribe expanding elements carried by said rotatable member and moving therewith, and means Jfor imparting a rotary motion to the rotatable member while simultaneously exerting a counter-rotary motion of lthe expanding elements and causing them to move outwardly in unison, whereby to expand the tube outwardly and spin kthe wall of the tribe forwardly longitudinally of the axis of the expanded wall, the said head having an annular groove in its abutting face concentric with the tube to receive the end of the tribe drawn through the opening.

3. A tool for expanding a tribe into an opening formed in a tube sheet, comprising a tubular member extending into the tube and having an enlarged head at one end thereof adapted to abut against the outer fill l0 lll face of the tube sheet, a plurality of frustoconical rollers extending lengthwise of the sleeve and arranged for movement outwardly against the inner wall of the tube, a tapered mandrel extending int-o the tubular body member and engaging the inner surfaces of the rollers whereby the rollers may be simultaneously moved outwardly and the rollers and body member frictionally driven in opposite directions, and means whereby the individual rotation of the rollers will cause the metal of the expanding wall to be drawn toward the end of the tube, the said head having a recess in its abutting face concentric with the opening in the tube sheet to permit slight projection of the tube beyond the outer face of the tube sheet without contact with said member or its head and thereby prevent upsetting of the end of the tube.

4f. A tube expanding tool comprising means including elements for expanding and spinning the metal at the end of' a tube to provide a tight joint between the end of the tube and an opening formed in a tube sheet and draw the metal of the tube slightly beyond the outer face of the tube sheet, said means including a hollow head provided with a shallow recess in its inner face adjacent its inner wall to receive the projecting end oiE the tube without contact of the tube with the walls of said recess whereby to prevent accidental upsetting or rupture of the projected end of the tube.

CARL F. BRAUN. 

